Variable capacity oil mist generator



- 1. 4 l mu s Jan. 29, 1957 F. G. SCHWEISTHAL 2,779,437

VARIABLE CAPACITY OIL MIST GENERATOR Filed dot. 15, 1953 2 Sheets-Sheet l WIN...

INVENTOR.

Jan. 29, 1957 F. G- SCHWEISTHAL 2,779,437

VARIABLE CAPACITY OIL MIST GENERATOR Filed Oct. 13, 1953 2 Sheets-Sheet 2 INVENTOR.

VARIABLE CAPACITY OIL MIST GENERATOR Frederick G. Schweisthal, Skokie, Ill., assignor to Stewart- Warner Corporation, Chicago, Ill., a corporation of Virginia Application October 13, 1953, SerialNo. 385,744

2 Claims. (31. 184- 55) The present invention relates to generators for supplying an aerosol or mist of atomized lubricating oil.

Oil mist lubricating systems of the type shown in Gothberg et al. Patent No. 2,642,156, are usually operated at a pressure of to p. s. i., depending upon the number and size of bearings connected to the system. In some installations incorporating conventional mist or aerosol generators, bearings having extremely close fits do not receive adequate lubrication because of insufiicient aerosol flow through such bearings when using these pressures. However, if the operating pressure of such conventional mist generators is increased to a value sufficient to force the aerosol into and through the bearings, the hearings will be overlubricated because of the high density of the lubricant particles in the aerosol.

'One object of the invention is to provide an improved aerosol generator having operational capabilities which are improved and perfected without adding substantially to the cost of the generator.

Other objects and advantages will be apparent from the following description of the form of the invention shown in the drawings in which:

Figure 1 is a side view of a generator embodying the invention;

Fig. 2 is a fragmentary sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view taken along the line 33 of Fig. 2; and

Fig. 4 is a detail view partially in section showing on an enlarged scale fiow restriction orifice means mounted in an air bypas to the mist outlet.

The oil mist or aerosol generator shown comprises a reservoir 10 bolted to the lower side of a downwardly open hollow casting 12. An oil pipe 14 extending upwardly from the lower end of the reservoir 10 is threaded into an internal boss 16 on one side of the casting 12 to communicate with a space 18 surrounding the throat of an atomizing venturi 20 formed in a plug 22 threaded into a radial bore in the boss.

Air under pressure from a line 24 connected to the casting 12 is supplied to the inlet end of the venturi 20 (the outer end in Fig. 3) through interconnected bores 26 and a pressure regulator 28 designed to maintain an adjustable predetermined pressure on the venturi. The regulator 28 comprises a valve 30 threaded into the casting 12 and controlled by suitable regulator structure mounted within a boss 32 (Fig. 3).

The flow of air through the venturi 20 causes a pres sure reduction in the venturi throat, which is connected to the space 18 through radial openings 34 in the plug 22. This suction draws oil up through an orifice 36 in the upper end of the pipe 14 to how into the venturi air stream through openings 34 (Figs. 2 and 3). The rate of oil flow is controlled by a needle valve assembly 38 threaded into a boss 40 on the top side of the casting 12 and extending downwardly into the orifice 36.

The stream of air and atomized oil issuing from the ired statcsmP Patented Jan. 29, 1957 inner end of the venturi and out through an outlet 44in the casting 12.

The volumeof the aerosol-thus produced is substantially increased and its pressure is multiplied by bypassing a controlled flow of air under pressure from the outlet of the pressure regulator .28 to the aerosol outlet 44 from the casting 12. As shown, a tube 46 is connected at one end to the lower opening of a T 48 fittedinto a hollow boss 47 to communicate through internal bores 50 with the pressure regulator outlet. The other end of the tube 46 is connected bya coupling 49 to a centrally bored manifold block 52 threaded into the casting l2 and forming the mist outlet 44. i

The rate of airflow through the bypass thus formed is controlled by a howres-triction orifice 54 formed in a disc 56 mounted inthe coupling 49 between the tube 46 and the manifold block 52 ('Fig. 4).

When the generator is in operation, supplying oil mist to bearings through a distributing system (not shown), the increase in the overall volume of the aerosol produced, due to the air bypassed through the flow restriction orifice 54 into the mist stream resultsin a very substantialbuild-up in the pressure level of the aerosol; The effective flow area of the bypass passage defined by the tube 46 and the coupling 49, including the apertured disc 56, is fixed at a predetermined value by the passage defining structure (principally the apertured disc) which is fixed against displacement by fluid pressure.

The overall volumetric rate at which the aerosol is formed can be varied by adjusting the regulator 28 to regulate the air pressure supplied to the venturi inlet and to the bypass through the orifice 54. This pressure is indicated by a suitable air gauge 60 connected to the upper opening of the T 48. The flow of oil into the air stream of the venturi 20 can be adjusted by the needle valve 38. Adjustment of the how rate of oil into the venturi air stream regulates the oil content or oil richness of the aerosol produced by the generator.

It will be appreciated that the oil content of the mist generated in the venturi 20 is substantially diluted and the volume of the mist is sharply increased by the restricted flow of air bypassed into the mist outlet 44. Since only a portion of the air going into the total mist output flows through the venturi 20, the increase in the rate of mist production realized by bypassing air into the mist stream is achieved without any necessity for modifying the mist generating venturi 2-0 or the air flow or oil flow regulating structure.

While I have shown and described a preferred embodiment of my invention, it will be apparent that numerous variations and modifications thereof may be made without departing from the underlying principles and scope of the invention. I therefore desire, by the following claims, to include all such variations and modifications by which substantially the results of my invention may be obtained through the use of substantially the same or equivalent means.

I claim:

1. An adjustable oil mist generator having a steppedup capacity to supply an aerosol of lubricating oil under various desired predetermined pressures and bearing oil particles entrained therein at various desired predetermined oil flow rates, comprising, in combination, an aerosol generating venturi, means defining an air inlet to said venturi, means defining an outlet for aerosol generated in said venturi, air supply means including an adjustable air pressure regulator connected to supply air to said venturi inlet at a pressure determined by adjustment of the regulator, means defining an air bypass passage having an inlet end connected to receive air from said regulator at the regulated pressure at which air is supplied to said venturi inlet, said bypass passage means including 20 flows around a 'bafile 42 to and said outlet and including adjustable flow control means for adjusting for any given rate of air flow through the venturi the flow of oil from the reservoir into the venturi, said adjustable flow control means being independent of said air supply means for said venturi inlet.

2. An adjustable oil mist generator having a stepped up capacity to operate against even very substantial back pressure to supply at a high volumetric rate adjustable over a wide range a lubricating oil aerosol having an oil richness that is adjustable independently of the rate at which the aerosol is supplied, said generator comprising, 0

in combination, an aerosol generating venturi having an air inlet and an aerosol outlet, air supply means including an adjustable air pressure regulator connected to supply air to said venturi inlet at a pressure determined by adjustment of the regulator, an oil reservoir communicating with said venturi outlet, means connecting said reservoir to said venturi between said inlet and said outlet thereof and including an adjustable needle valve positioned for adjusting for any given rate of air flow through the venturi the flow of oil from the reservoir into the venturi, said needle valve being independent of said air supply means for said venturi inlet, means including a generator out-let positioned to collect the aerosol output of said venturi outlet, an air bypass tube connected at one end to receive air from said air regulator at the regulated pressure at Which air is supplied to said venturi inlet, means connecting the other end of said tube to said generator outlet, a disc defining a restricted air bypass orifice therethrough, and means supporting said disc in transverse relation to the outlet end of said tube to restrict the outflow of air from said tube to 15 passage through said orifice as a high speed stream issuing into said generator outlet.

References Cited in the file of this patent UNITED STATES PATENTS 1,113,276 Woodmansee Oct. 13, 1914 2,610,700 Goth'berg Sept. 16, 1952 2,613,067 Goodyer Oct. 7, 1952 FOREIGN PATENTS 408,900 Great Britain Apr. 19, 1934 

